This is Steve Ember with the VOA Special English program, IN THE NEWS.

United States officials called on the public Friday for more help in finding whoever is responsible for sending anthrax in the mail system. They said they had hoped a government offer of one-million dollars would have produced more information by now.

In the past month, doctors have confirmed at least sixteen cases of people on the East Coast with lung or skin infections from anthrax bacteria. Most have been postal handlers or connected to the media. Four of the people have died -- two in Washington, D-C, one in New York and one in Florida.

The investigation has centered on Trenton, New Jersey. At least three letters containing anthrax bacteria were mailed from there. Two went to news organizations in New York, the third to the office of the Senate majority leader in Washington. That letter passed through Washington's main post office. Two workers there later died of anthrax.

Discoveries of even small amounts of anthrax have led to the closing of postal centers, government mailrooms and congressional office buildings. Friday, the Supreme Court returned to its own building after meeting in another courthouse this week.

The Postal Service has reacted to the situation by starting to treat some mail with germ-killing radiation.

The anthrax cases began to appear not long after the September eleventh terrorist attacks in New York and Washington. Investigators, however, say they have yet to prove a connection.

This week, a sixty-one-year-old hospital worker in New York City died of inhalation anthrax. Health officials say the anthrax that killed Kathy Nguyen matches the bacteria found in the three letters sent from Trenton.

Her case, though, was a mystery. Investigators said they had found no evidence linking her death to infected mail. They began going back over her movements and speaking to people she knew, hoping to learn how she became infected.

For a long time, there have been fears of anthrax being turned into a biological weapon.

Anthrax can be found anywhere in the world, especially in agricultural areas, where animals become infected. The most common form of infection in people is cutaneous anthrax. The bacteria can enter through a cut in the skin. This kind of anthrax is easily treated.

People can get intestinal anthrax from eating the meat of infected animals. Inhalation anthrax, the most severe form of the disease, happens when a person breathes the bacteria spores into the lungs.

Experts say anthrax cannot spread from one person to another.

Doctors treat anthrax with antibiotics. These medicines can be highly effective if begun early. Some people are now taking antibiotics to prevent any possible anthrax infection.

However, experts warn against taking antibiotics unless there is a real need. Some people suffer bad effects, and overuse can make antibiotics less effective against the extremely small organisms they are designed to kill.

This VOA Special English program, IN THE NEWS, was written by Cynthia Kirk. This is Steve Ember.